Electric blower

ABSTRACT

Disclosed herein is an electric blower capable of preventing grease stored in a boss part of a bracket from being leaked and/or evaporated. The electric blower includes: a housing receiving a stator, a rotating shaft, and rotor; a housing cover covering an upper opening part of the housing; and a bracket including a boss part which protrudes vertically upward in a cylindrical shape at a central portion thereof to receive an upper bearing and the rotating shaft and a flange which radially elongates outward from the boss part to be coupled with the housing and rotatably supporting the rotating shaft, wherein the boss part includes a disk-shaped flat upper surface having a shaft hole helping penetration of the rotating shaft, a cylindrical side wall extending downward from an edge of the upper surface, and at least one guide groove formed at a lower portion of the upper surface.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of Korean Patent Application No. 10-2013-0068342, filed on Jun. 14, 2013, entitled “Electric Blower” which is hereby incorporated by reference in its entirety into this application.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to an electric blower.

2. Description of the Related Art

Generally, an electric blower (for example, a motor for a vacuum cleaner) includes a housing having a receiving space formed therein, a stator fixedly disposed in the housing, a rotor rotatably disposed in the stator, and a rotating shaft integrally coupled with a shaft center of the rotor. Further, the electric blower includes a bearing housing supporting the rotating shaft of the rotor between a guide vane and a motor disclosed in Patent Document 1, in which the bearing housing supports the rotating shaft at a central portion thereof and an edge thereof is fixed to a motor housing.

The bearing housing of Patent Document 1 includes a shaft support part which supports the rotating shaft of the motor along with a channel forming part forming a channel by contacting a bottom end of a return vane providing an optimal channel area to solve an incomplete channel occurring due to a small return vane. However, a problem in that grease stored in the bearing housing is leaked through a void between the bearing and the rotating shaft disposed across a shaft hole of the bearing has not yet been solved.

Unlike this, the electric blower (Patent Document 2) according to the related art includes a bracket designed to fix an impeller housing, supporting the rotating shaft so as to prevent the grease stored in the bearing housing from being leaked, in which the bracket includes a boss part separately provided with an oil sealing part to prevent the grease from being leaked. The electric blower goes against a current trend of miniaturization and/or weight reduction, needs to be structurally dense, and causes a considerable problem of durability due to an increase in the number of parts.

PRIOR ART DOCUMENT Patent Document

-   Patent Document 1: Korean Patent Laid-Open Publication No.     10-2008-0018744 -   Patent Document 2: US Patent Laid-Open Publication No. US     2003/0151320

SUMMARY OF THE INVENTION

The present invention has been made in an effort to provide an electric blower capable of minimizing an oil leakage phenomenon by forming a guide groove in a boss part of a bracket supporting a rotating shaft.

According to a preferred embodiment of the present invention, there is provided an electric blower, including: a housing receiving a stator, a rotating shaft, and rotor; a housing cover covering an upper opening part of the housing; and a bracket including a boss part which protrudes vertically upward in a cylindrical shape at a central portion thereof to receive an upper bearing and the rotating shaft and a flange which radially elongates outward from the boss part to be coupled with the housing and rotatably supporting the rotating shaft, wherein the boss part includes a disk-shaped flat upper surface having a shaft hole helping penetration of the rotating shaft, a cylindrical side wall extending downward from an edge of the upper surface, and at least one guide groove formed at a lower portion of the upper surface.

The at least one guide groove may be arranged at a lower portion of the upper surface along a circumferential surface of the shaft hole to move grease along the guide groove at the time of the rotation of the rotating shaft, thereby preventing the grease from being leaked to the outside through the shaft hole.

Optionally, the at least one guide groove may be spaced apart from each other at equidistance along the circumference of the shaft hole.

The at least one guide groove may be formed to be curved in a spiral direction.

The spiral direction of the at least one guide groove may be formed in a rotation direction of the rotating shaft and the at least one guide groove may be designed so as not to affect a driving of the electric blower by matching a flowing direction of the grease with the rotation direction of the rotating shaft.

The at least one guide groove may be formed to have a depth reduced toward the side wall from the shaft hole.

The at least one guide groove may be formed to have a width narrowed toward the side wall from the shaft hole.

The boss part may further include a triangular section-shaped protrusion which is inclined upward toward an outside from the circumference of the shaft hole.

The protrusion of the boss part may be formed in a right-angled triangular section shape to extend a support area of the rotating shaft and extends a length between the rotating shaft and the shaft hole to provide a sealing effect of the grease.

The protrusion may protrude downward from the lower portion of the upper surface.

The protrusion may have the at least one guide groove formed on an inclined surface thereof to forcibly move the grease into the boss part by rotating the rotating shaft.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a perspective view of an electric blower according to a preferred embodiment of the present invention when being viewed from the top;

FIG. 2 is a longitudinal cross-sectional view taken along the line in FIG. 1;

FIG. 3 is an enlarged view illustrating a circular arc part of FIG. 2;

FIG. 4 is a bottom diagram of a bracket to be mounted in the electric blower according to the preferred embodiment of the present invention; and

FIG. 5 is a partially enlarged view of the bracket mounted in the electric blower according to another preferred embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The objects, features and advantages of the present invention will be more clearly understood from the following detailed description of the preferred embodiments taken in conjunction with the accompanying drawings. Throughout the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant descriptions thereof are omitted. Further, in the following description, the terms “first,” “second,” “one side,” “the other side” and the like are used to differentiate a certain component from other components, but the configuration of such components should not be construed to be limited by the terms. Further, in the description of the present invention, when it is determined that the detailed description of the related art would obscure the gist of the present invention, the description thereof will be omitted.

Hereinafter, an electric blower according to preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIGS. 1 to 3, an electric blower 1 according to a preferred embodiment of the present invention is, in particular, a motor assembly for a vacuum cleaner and includes a housing 20 having a receiving space formed therein and a housing cover 10 covering an upper opening part of the housing.

The housing cover 10 is configured to have a cup shape which is overturned to protect an impeller 60, a diffuser 70, a bracket 80, and the like, and is disposed on the upper opening part of the housing 20. The housing cover 10 includes a suction hole (no reference numeral) disposed at a central portion thereof so as to forcibly introduce air outside the electric blower 1 by rotating the impeller 60 at the time of applying power and may be formed in a cylindrical shape as illustrated.

The housing cover 10 may be coupled with the housing 20 by various methods, such as bonding coupling, press-fitting coupling, and screw coupling.

The impeller 60 is fixedly disposed to an upper end of a rotating shaft 50, in more detail, axially coupled with an upper portion of a diffuser 70. The impeller 60 is fixedly disposed to the rotating shaft 50 and thus receives a rotational motion of a rotor 40. The rotational motion of the impeller 60 provides a centrifugal force around the impeller 69 and the centrifugal force may enable external air outside the electric blower 1 to be sucked while discharging air at a center of the impeller 60 to an edge of the impeller 60, that is, in an outward direction through a suction hole (no reference numeral).

In summary, the diffuser 70 is disposed to be spaced apart from the outside of the impeller 60 at a predetermined interval so as to rotate the impeller 60 by being axially coupled with the upper portion of the bracket 80. The diffuser 70 guides air introduced at a high speed by rotating the impeller 60 into the electric blower 1 of the present invention.

The housing 20 is formed in a cylindrical shape opened upward and as illustrated, receives the stator 30 disposed therein and the rotor 40 rotating based on the rotating shaft 50 and disposed at a center of the stator 30. The rotating shaft 50 extends axially while forming a rotation center of the electric blower 1. A side of the housing 20 is provided with a discharge hole 21 which penetrates through the inside and outside of the housing 20.

The rotor 40 has a hollow hole formed at a center of a rotor core, in which the hollow hole is fixedly coupled with the rotating shaft 50 to transfer the rotation of the rotor 40 to the outside.

The stator 30 is provided with a stator yoke having a donut shape to receive the rotor 40 and an inside of the stator yoke may be provided with a plurality of salient poles. When a current is applied to the stator 30, a flux path is formed by the rotor 40 facing the stator 30, such that the rotor 40 may rotate to generate power.

As known well, the stator 30 includes an armature, while the rotor 40 includes the rotating shaft 50 and a magnet. Further, the stator 30 is mounted in the housing 20 as illustrated.

To output the rotation power of the rotor 40 to the outside, the rotating shaft 50 of the rotor 40 is supported to the electric blower 1 by bearings 100 and 110.

In detail, the upper bearing 100 is included in a boss part 81 for receiving the bearing so as to allow the bracket 80 to support one end of the rotating shaft 50. The bracket 80 is positioned in a seating part 28 disposed on a side of an upper edge of the housing 20 by a screw fastening type.

To correspond thereto, the housing 20 includes a bearing receiving part 22 so that the other end of the rotating shaft 50 is supported by the housing 20. The bearing receiving part 22 receives the lower bearing 110.

Optionally, the bearings 100 and 110 may be implemented by a ball bearing, but various types of bearing may also be adopted without being limited thereto. A predetermined space part 81 d is formed between the upper bearing 100 and the boss part 81 and grease G which is working oil is injected into the space part to be able to secure a storage space of the working oil. The leakage and evaporation of the grease G accelerate abrasion of the bearing, affect an increase in temperature of the electric blower, and cause a decrease in lifespan of the electric blower at the time of high-speed rotation.

Similarly thereto, a predetermined space part is formed between the lower bearing 110 and the bearing receiving part 22 and the grease G which is the working oil is injected into the space part to secure the storage space of the working oil.

In particular, according to the electric blower 1 according to the preferred embodiment of the present invention, at least one guide groove 81 e is included in the boss part 81 to be able to prevent or minimize the leakage of the grease G stored in the boss part 81 to the outside.

Generally, the grease G is leaked to the outside through a void between the rotating shaft 50 and a shaft hole 81 a of the boss part 81. Therefore, the preferred embodiment of the present invention continuously promotes a flow of the grease G within the space part 81 d to prevent or minimize the leakage of the grease G through the void between the rotating shaft 50 and the shaft hole 81 a of the boss part 81.

The grease G filled in the space part 81 d is forcibly guided to a cylindrical side wall 81 c of the boss part 81 in an arrow direction through the guide groove 81 e at the time of rotating the rotating shaft 50, and thus may be rapidly deviated from the void between the rotating shaft 50 and the shaft hole 81 a, thereby reducing an opportunity of the leakage and evaporation of the grease G.

FIG. 4 is a bottom diagram of the bracket to be mounted in the electric blower according to the preferred embodiment of the present invention.

As illustrated, the bracket 80 according to the preferred embodiment of the present invention includes a boss part 81 which protrudes vertically upward in a cylindrical shape at a central portion thereof to receive the rotating shaft 50 (see FIG. 2) and a flange 82 which radially elongates outward from the boss part 81.

The bracket 80 supports the rotating shaft 50 by the boss part 81 and at the same time, the edge of the bracket is fixed to the housing 20. In detail, the flange 82 is screwed with the seating part 28 of the housing 20 illustrated in FIG. 2 to be seated thereon, thereby helping the screwing between the bracket 80 and the housing 20.

In detail, the boss part 81 is configured of a disk-shaped upper surface 81 b and a cylindrical side wall 81 c extending downward from an edge of the upper surface 81 b to be formed in a cylindrical shape which protrudes vertically upward. The boss part 81 of the bracket 80 may store the grease G in the space part 81 d between the cylindrical boss part 81 and the upper bearing 100 mounted to be spaced apart from the upper surface 81 b of the boss part 81. In particular, the boss part 81 according to the preferred embodiment of the present invention forms the shaft hole 81 a helping the penetration of the rotating shaft 50 on the upper surface 81 b and at least one guide groove 81 e along the circumference of the shaft hole 81 a. Optionally, the guide grooves 81 e may be spaced apart from each other at equidistance along the circumference of the shaft hole 81 a.

Further, the guide groove 81 e is designed to have a depth reduced or a width narrowed toward the side wall 81 c from the shaft hole 81 a, such that the grease G may easily flow toward the side wall 81 c without being hindered. In addition, the guide groove 81 e may be designed to have the depth reduced and the width narrowed toward the side wall 81 c from the shaft hole 81 a.

Preferably, the guide groove 81 e according to the preferred embodiment of the present invention may be formed to be curved in a spiral shape as illustrated. The spiral direction of the guide groove 81 e may be formed in a rotation direction of the rotating shaft 50. The guide groove 81 e may follow the rotation of the rotating shaft 50 to improve the flowing speed of the grease G and may allow the grease to be rapidly deviated from the void between the rotating shaft 50 and the shaft hole 81 a of the boss part 81, thereby minimizing the opportunity of the oil leakage through the void.

The electric blower 1 according to the present invention designed to have the structure to prevent the grease G from being leaked may extend the lifespan of the upper bearing 100, thereby keeping the reliable driving state of the electric blower 1.

FIG. 5 is a cross-sectional view illustrating a portion of the bracket to be mounted in the electric blower according to another preferred embodiment of the present invention.

The electric blower according to another preferred embodiment of the present invention incurs a labyrinth sealing phenomenon in the void so as to maximally prevent the grease G from being leaked and/or evaporated through the void between the rotating shaft 50 and the shaft hole 81 a of the bracket 80.

In detail, the preferred embodiment of the present invention includes the bracket 80 which is configured of the cylindrical boss part 81 supportably receiving the rotating shaft 50 and the flange 82 fixed to the housing 20 which radially elongates outward from the boss part 81.

In particular, the boss part 81 includes the disk-shaped upper surface 81 b having the shaft hole 81 a helping the penetration of the rotating shaft 50 disposed at the central portion thereof, the cylindrical side wall 81 c which extends downward from the edge of the upper surface 81 b, the space part 81 d defined by the upper surface 81 b, the side wall 81 c, the rotating shaft 50, and the bearing 100 to receive the grease G, and a triangular section-shaped protrusion 81 f protruding from the lower portion of the upper surface 81 b along the circumference of the shaft hole 81 a. For reference, the flange 82 extends from the outer circumference surface of the side wall 81 c of the boss part 81.

Preferably, the triangular section-shaped protrusion 81 f protrudes downward from the lower portion of the upper surface to be inclined upward toward the outside from the center of the shaft. More preferably, the protrusion 81 f may provide a predetermined void from the outer circumferential surface of the rotating shaft 50 to keep a contactless state, thereby being formed in a right-angled triangular section shape.

According to the preferred embodiment of the present invention, a cross sectional area of the void (in other words, the oil leakage path) between the rotating shaft 50 and the protrusion 81 f is substantially more narrow than that of the space part 81 d, such that the labyrinth sealing effect may be expected. In addition, the protrusion 81 f may serve to support the rotating shaft 50 along with the bearing 100, such that the verticality of the rotating shaft 50 may be improved.

In addition, the inclined surface of the protrusion 81 f is provided with at least one guide groove 81 e, in which the guide grooves 81 e are disposed to be spaced apart from each other at equidistance along the circumference of the inclined surface of the protrusion 81 f.

As set forth above, according to the electric blower according to the preferred embodiments of the present invention, it is possible to prevent or minimize the leakage of the grease stored in the boss part of the bracket.

In particular, according to the preferred embodiments of the present invention, it is possible to stably store the grease in the boss part using the rotation of the rotating shaft by forming the plurality of guide grooves at a lower portion of an upper surface of the boss part of the bracket.

According to the preferred embodiments of the present invention, it is possible to provide the structural simplification and the convenience of the assembling by not requiring the separate components for preventing the grease from being leaked.

According to the preferred embodiments of the present invention, the bracket can increase the oil storing performance in the boss part, thereby extending the lifespan of the upper bearing and securing the reliable driving state of the electric blower.

Although the embodiments of the present invention have been disclosed for illustrative purposes, it will be appreciated that the present invention is not limited thereto, and those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention.

Accordingly, any and all modifications, variations or equivalent arrangements should be considered to be within the scope of the invention, and the detailed scope of the invention will be disclosed by the accompanying claims. 

What is claimed is:
 1. An electric blower, comprising: a housing receiving a stator, a rotating shaft, and rotor; a housing cover covering an upper opening part of the housing; and a bracket including a boss part which protrudes vertically upward in a cylindrical shape at a central portion thereof to receive an upper bearing and the rotating shaft and a flange which radially elongates outward from the boss part to be coupled with the housing and rotatably supporting the rotating shaft, wherein the boss part includes a disk-shaped flat upper surface having a shaft hole helping penetration of the rotating shaft, a cylindrical side wall extending downward from an edge of the upper surface, and at least one guide groove formed at a lower portion of the upper surface.
 2. The electric blower as set forth in claim 1, wherein the at least one guide groove is formed at the lower portion of the upper portion along a circumferential surface of the shaft hole.
 3. The electric blower as set forth in claim 2, wherein the at least one guide groove is spaced apart from each other at equidistance along the circumference of the shaft hole.
 4. The electric blower as set forth in claim 1, wherein the at least one guide groove is formed to be curved in a spiral direction.
 5. The electric blower as set forth in claim 4, wherein the spiral direction of the at least one guide groove is formed in a rotation direction of the rotating shaft.
 6. The electric blower as set forth in claim 1, wherein the at least one guide groove has a depth reduced toward the side wall from the shaft hole.
 7. The electric blower as set forth in claim 1, wherein the at least one guide groove has a width narrowed toward the side wall from the shaft hole.
 8. The electric blower as set forth in claim 1, wherein the boss part further includes a triangular section-shaped protrusion which is inclined upward toward an outside from the circumference of the shaft hole.
 9. The electric blower as set forth in claim 8, wherein the protrusion of the boss part is formed in a right-angled triangular section shape.
 10. The electric blower as set forth in claim 8, wherein the protrusion protrudes downward from the lower portion of the upper surface.
 11. The electric blower as set forth in claim 8, wherein the protrusion has the at least one guide groove formed on an inclined surface thereof. 